1. Field of the Invention
This invention relates to a structure of plasma display panels.
The present application claims priority from Japanese Application No. 2004-312466, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
A surface-discharge-type alternating-current plasma display panel (hereinafter referred to as “PDP”) has two opposing glass substrates placed on both sides of a discharge-gas-filled discharge space. One of the two glass substrates has row electrode pairs extending in the row direction and regularly arranged in the column direction. The other glass substrate has column electrodes extending in the column direction and regularly arranged in the row direction. Unit light emission areas (discharge cells) are formed in matrix form in positions corresponding to intersections between the row electrode pairs and the column electrodes in the discharge space.
The PDP further has a dielectric layer covering the row electrodes and/or the column electrodes. A magnesium oxide (MgO) film is evaporated onto a position of the dielectric layer facing each of the unit light emission areas. The MgO film has the function of protecting the dielectric layer and the function of emitting secondary electrons into the unit light emission area.
A simple and convenient method of forming the MgO film in the manufacturing process for the PDPs is to use a screen printing technique of applying a coating of a paste in which MgO powder is mixed to the dielectric layer to form an MgO film. Consequently, this technique has been considered for adoption as described in Japanese Patent Laid-open Application No. 6-325696, for example.
As described here in the related art, screen printing is used to apply a coating of a paste mixed with a polycrystalline floccules type magnesium oxide obtained by heat-treating and purifying magnesium hydroxide to form a magnesium oxide film for a PDP. In this case, however, the discharge characteristics of the PDP are merely of an extent equal to or slightly greater than that of a PDP having a magnesium oxide film formed by the use of evaporation technique.
An urged need arising from this is to form a magnesium oxide film (i.e. a protective film) capable of yielding a greater improvement in the discharge characteristics of the PDP.